* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download The Science of Biology Ch 1 HB_2016
Survey
Document related concepts
Sexual selection wikipedia , lookup
Natural selection wikipedia , lookup
Symbiogenesis wikipedia , lookup
Transitional fossil wikipedia , lookup
Precambrian body plans wikipedia , lookup
Evidence of common descent wikipedia , lookup
Theistic evolution wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Evolving digital ecological networks wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Saltation (biology) wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Koinophilia wikipedia , lookup
Transcript
Evolution and the Foundations of Biology Chapter 1 Overview: Inquiring About Life An organism’s adaptations to its environment are the result of evolution For example, a beach mouse’s light, dappled fur acts as camouflage, allowing the mouse to blend into its surroundings Inland mice of the same species are darker in color, matching their surroundings Evolution is the process of change that has transformed life on Earth What is Biology? Biology is the scientific study of life Biologists ask questions such as How does a single cell develop into an organism? How does the human mind work? How do different forms of life in a forest interact? Study of Living Things Biology is the study of living things Comes in a variety of shapes & forms Biologists study life in many different ways Also the study of diversity (how living things work, interact in their environment, & how they change over time) WHAT CHARACTERISTICS DEFINE LIFE? All living organisms share a basic characteristic Properties (or Characteristics) of Life: 1. Cellular organization: all organisms consist of one or more cells (or order within internal & external parts and how they interact with the world) 2. Order: all living things are highly ordered…we have many different types of cells 3. Sensitivity: all organisms respond to stimuli 4. Growth, development, and reproduction: must pass on our genetics Properties (or Characteristics) of Life: 5. Energy utilization: all organisms use energy in our body(this energy depends on metabolism) 6. Evolutionary adaptation: all organisms interact with other organisms & the environment for survival. 7. Homeostasis: internal conditions suitable for their environment Think about this…. What must all living organisms be able to do to be considered to be living?….thumbs up if you know! Studying diverse forms of life reveals common themes To organize and make sense of all the information encountered in biology, focus on a few big ideas These unifying themes help to organize biological information 4 Themes that Unify Biology 1. Theme: Different levels of Biological Organization Hierarchical Organization of the Biological World The study of life extends from microscopic molecules to the global scale of the earth 1. Population Level 2. Organism Level 3. Cellular Level 1 The Biosphere 7 Tissues 2 Ecosystems 6 Organs and Organ Systems 10 Molecules 3 Communities 8 Cells 5 Organisms 4 Populations 9 Organelles Population Level Biosphere: consist of life on earth and the places where life exist Ecosystem: the community & habitat where it lives together in an ecological system Community: all the populations of different species living together in one place Population: most basic a group of organism of the same species living in the same place Species/Organism: its members similar in appearance are able to interbreed 1 The Biosphere Fig. 1.2c4 Fig. 1.2c3 Fig. 1.2c1 Fig. 1.2b4 Organismal Level Organ systems: are groups of organs (I.e. the nervous system consist of sensory organs used by the brain, spinal cord & neurons that send signals to & from them) Organs: are groups of tissues (i.e. brain is an organ made of nerve cells & connective tissue) Tissues: the most basic level which are groups of similar cells Tissue Organ Organ system Organism Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fig. 1.2b3(TE Art) Organ system Organ system Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. organ Organ Fig. 1.2b1 Cellular Level Cells are the basic unit of life Organelles are tiny organs of the cell Molecules are clusters of atoms Atoms are the basic units of matter Atoms Molecule Organelle Cell Fig. 1.2a5 Fig. 1.2a4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. molecules Molecule Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. atoms Atoms Emergent Properties Emergent properties result from the arrangement and interaction of parts within a system Emergent properties characterize nonbiological entities as well For example, a functioning bicycle emerges only when all of the necessary parts connect in the correct way Systems in Biology Biologists today combine reductionism with systems biology, the exploration of a biological system by analyzing the interactions among its parts The systems approach poses questions such as How does a drug for blood pressure affect other organs? How does increasing CO2 alter the biosphere? Structure and Function At each level of the biological hierarchy we find a correlation between structure and function Analyzing a biological structure can give clues about what it does and how it works 2. Theme: Life’s processes involve the expression of Genetic Information Genes are made of DNA Heredity depends on the copying of DNA from one generation to the next Genome: entire set of DNA instructions within a cell DNA Double Helix 3. Theme: Life Requires the Transfer and Transformation of Energy and Matter Input of energy, mainly from the sun, and transformation of energy from one form to another make life possible Plants and other photosynthetic organisms convert the energy of sunlight into the chemical energy of sugars This chemical energy of these producers is then passed to consumers that feed on the producers Energy flows through an ecosystem, generally entering as light and exiting as heat Chemical elements are recycled within an ecosystem Energy flow Chemicals pass to organisms that eat plants. Light energy Chemical energy Chemical elements Heat Decomposers return chemicals to soil. 4. Theme: Organisms Interact with Other Organisms and the Physical Environment Every organism interacts with physical factors in its environment Both organisms and their environments are affected by the interactions between them For example, a tree takes up water and minerals from the soil and carbon dioxide from the air; the tree releases oxygen to the air, and roots help form soil Interactions between organisms include those that benefit both organisms and those in which both organisms are harmed Interactions affect individual organisms and the way that populations evolve over time The Core Theme of Biology: Evolution Evolution makes sense of everything we know about living organisms: Evolution explains patterns of unity and diversity in living organisms Similar traits among organisms are explained by descent from common ancestors Differences among organisms are explained by of inheritable changes Evolution Classifying the Diversity of Life: The Three Domains of Life Humans group diverse items according to their similarities and relationships to each other Studies of form and function has been used to classify life-forms Recently, new methods of assessing species relationships, especially comparisons of DNA sequences, have led to a reevaluation of larger groupings Biologists categorize all living things Into 3 groups called domains The 3 Domains of Life 3 Biological Domains: 1. Bacteria (prokaryotic cells) 2. Archaea (prokaryotic cells) 3. Eukarya (eukaryotic cells) A. Protista B. Plantae C. Fungi D. Animalia 2 m 2 m (b) Domain Archaea (a) Domain Bacteria (c) Domain Eukarya Kingdom Animalia 100 m Kingdom Plantae Kingdom Fungi Protists Darwin’s theory of evolution illustrates how science works The Science of Biology Nearly 180 yrs ago, Charles Darwin set sail on a journey on board the H.M.S. Beagle His findings led directly to his development of the Theory of Evolution This theory has become the core of the science of biology Charles Darwin English Naturalist: 5 year voyage around coasts of South America Studied and made observations for over 30 years of various plants and animals Wrote “On the Origin of Species” Living things have changed during the course of life on earth His theory of natural selection did not challenge the existence of a Divine Creator-He believed that this Creator did no simply create things and then leave them forever unchanged. Instead He expressed himself through the operation of natural laws that produced change over time, thus evolution. Charles Darwin published On the Origin of Species by Means of Natural Selection in 1859 Darwin made two main points 1. Species showed evidence of “descent with modification” from common ancestors 2. Natural selection is the mechanism behind “descent with modification” Darwin’s theory captured the duality of unity and diversity Darwin observed that Individuals in a population vary in their traits, many of which are heritable More offspring are produced than survive, and competition is inevitable Species generally suit their environment Darwin determined: Individuals that are best suited to their environment are more likely to survive and reproduce Over time, more individuals in a population will have the advantageous traits other words, the environment “selects” for the propagation of beneficial traits Darwin called this process natural selection In Darwin’s Evidence Drew ideas from Charles Lyell’s “Principles of Geologyspecies were becoming extinct while others were emerging 1.Observed fossils of extinct armadillos (Glyptodonts) that were similar to armadillos still living in the area-Why would similar living and fossil organisms be in the same area unless the earlier form had given rise to the other? In rock strata, progressive changes in characteristics can be seen in fossils from earlier and earlier layers. 2. Geographical Distribution a. Lands with similar climates (Australia, S. Africa, California, and Chili), have unrelated plants and animals indicating that diversity is not entirely influenced by climate and environment. b. The plants and animals of each continent are distinctive. 3. Oceanic Islands a. Endemic species show relatedness to one anotherThis suggests that they developed after their mainland ancestors reached the islands. (Galapagos tortoises) b. Species on oceanic island show strong affinities to those on the nearest mainland. (Galapagos finches) One example: the Galapagos On the Galapagos Islands, Darwin studied many species of animals and plants that are unique to the islands but similar to species elsewhere. He realized that individuals struggle to compete in changing environmental conditions. Galapagos tortoise are the largest On Earth, different from other Tortoises in body size and shape Galapagos finch Is adapted to feed On cacti. Galapagos marine iguanas Eat algae from the ocean Large claws help to cling To slippery rocks Natural Selection Natural selection is a mechanism for change in populations. It occurs when organisms with favorable variations survive, reproduce, and pass their variations to the next generation. As a result, each generation consists largely of offspring from parents with these variations that aid survival. In nature, organisms produce more offspring than can survive Darwin proposed this idea of natural selection to explain how species change over time Darwin explains natural selection In any population, individuals have variations. Fishes, for example, may differ in color, size, and speed. Darwin explains natural selection Individuals with certain useful variations, such as speed, survive in their environment, passing those variations to the next generation. Darwin explains natural selection Over time, offspring with certain variations make up most of the population and may look entirely different from their ancestors. The Effects Of Natural Selection Natural selection can significantly alter the genetic equilibrium of a population’s gene pool over time Significant changes in the gene pool could lead to the evolution of a new species over time Speciation • The evolution of new species, a process called speciation occurs when members of similar populations no longer interbreed to produce fertile offspring within their natural environment. Geographic Isolation Geographic isolation occurs whenever a physical barrier divides a population Isolated habitat fragments are similar to islands in the way in which the species living there are effected. https://www.youtube.com/watch?v=BE77igZczlI GEOGRAPHIC ISOLATION Artificial Selection artificial selection is the process of intentional or unintentional modification of a species through human actions which encourage the breeding of certain traits over others Darwin hypothesis that there was a force in nature that worked like artificial selection Adaptations for Evolution According to Darwin’s theory, adaptations in species develop over many generations. Evolution after Darwin: More Evidence More extensive fossil record -support Darwin’s theory of natural selection Mechanism of heredity-Genetics accounts in a neat and orderly way for the production of new variations in organisms Comparative Anatomy Molecular evidence: -DNA evidence Other Evidence Anatomy Homologous Structures: Similar In arrangement, function or in both Analogous Structures: Similar body parts in function w/ no evolutionary origin Vestigial Structure: A body structure in a present day organism That no longer serves its original purpose, but was useful to An ancestor Human Cat Bat Porpoise Horse Fossil Evidence Fossils are important in Evolution Because they provide a record Of early life and history Fossils – the clues to the past About 95 percent of the species that have existed are extinct— they no longer live on Earth Among other techniques, scientists study fossils to learn about ancient species. Scientific Method The experimental testing of a hypothesis formulated after the systematic, objective collection of data The Nature of Science Biology is FACINATING…AND IMPORTANT Biologists are working on cures for disease such as AIDS & cancer Explains what our world is like Solve environmental problems Use and discover new technology Scientific Method Scientific Method The methods of science are based on 2 principles: 1. Events in the natural world have natural causes Ex: ancient Greeks believed that lightning & thunder occurred b/c a supernatural god Zeus hurled thunderbolts from the heavens Scientific Method 2 principles 2. Uniformity: is the idea that the fundamental laws of nature operate the same way at all places and at all times Ex: scientists assume that the law of gravity works the same way on Mars as it does on Earth. How Science Is Done 1. Observation or Ask a Question 2. Do background research 3. Hypothesis 4. Controlled Experiment (test hypothesis) 5. Collect & Analyze Data 6. Draw a Conclusion 7. Develop Theory Hypotheses are accepted or rejected based on experimental results. Biologist reason in 2 ways: 1. Deductive Reason 2. Inductive Reason Deductive Reasoning Applies general principles to predict specific results. Logic flows from general to specific The hypothesis is then tested experimentally Inductive Reasoning: Draws conclusions through the logical process Applies specific principles to predict general results. Generalizations are drawn from a large number of observations Example: Cats have fur, dogs have fur, and every mammal you observe has fur, then you may infer that all mammals have hair. Example: “all organisms are made of cells” was based on two centuries of microscopic observations Establishing Controls (variables) Independent Variable: the manipulated variable (changing) Dependent Variable: responding variable, it is affected by the independent variable (happens because of something) If a scientist conducts an experiment to test the theory that a vitamin could extend a person’s life-expectancy, then: The independent variable is the amount of vitamin that is given to the subjects within the experiment. This is controlled by the experimenting scientist. The dependent variable, or the variable being affected by the independent variable, is life span. In Other Words….. The dependent variable is usually the result of the experiment, the thing you measure. The independent variable is what causes the results. Using Conclusions A hypothesis is most useful when it makes predictions, because predictions provide a way to test the validity of the hypothesis If experimental results are inconsistent with the predictions then the hypothesis must be rejected. If experimental results are consistent with the predictions then the hypothesis must be accepted. Mythbusters… https://www.youtube.com/watch?v=iHu6LV g-0Hs Waterslide wipeout Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Observation Question Hypothesis Hypothesis Hypothesis Hypothesis Hypothesis Potential hypotheses 1 2 3 4 5 Fig. 1.4 Experiment Hypothesis 2 Hypothesis 3 Hypothesis 5 Remaining possible hypotheses Reject hypotheses 1 and 4 Experiment Hypothesis 5 Reject hypotheses 2 and 3 Last remaining possible hypothesis Predictions Experiment 1 Experiment 2 Experiment 3 Predictions confirmed Experiment 4 Basic vs Applied Research Basic research expands the boundaries of what we know and is usually performed at Universities Applied research is conducted by scientists in industry. Example food additives, new drugs, testing environmental quality